Recording medium having data structure for managing reproduction of at least video data representing multiple reproduction paths and recording and reproducing methods and apparatuses

ABSTRACT

In the data structure, a data area of the recording medium stores a transport stream of at least video data. The transport stream is divided into transport packets, and each of the transport packets is associated with one of the multiple reproduction paths. Also, the transport packets of each reproduction path is stored in separate physical domains of the data area from one another.

RELATED APPLICATION DATA

[0001] This is a continuation of application Ser. No. 10/176,364 filedJun. 20, 2002; the contents of which is hereby incorporated by referencein its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a recording medium having a datastructure for managing reproduction of at least video data representingmultiple reproduction paths as well as methods and apparatuses forreproduction and recording.

[0004] 2. Description of the Related Art

[0005] Owing to technical improvement in the fields of video/audio datacompression, digital modulation/demodulation, and so on, a digitaltelevision broadcast system broadcasting TV signals in the form ofdigital data stream is being standardized rapidly.

[0006] In the digital television broadcast system, audio/video (A/V)signals to be broadcasted are compressed according to the datacompressing rule specified by MPEG 2 (Moving Picture Experts Group) andthe compressed A/V data are broadcasted in the form of transport stream(TS), which is also defined in MPEG 2 standard, composed of successive188-byte-long transport packets (TPs).

[0007] The digital TV broadcast system, which will be commercializedsoon owing to technical improvement of A/V data compression andtransmission, is able to support much higher-quality of video and audiothan an analog TV system. Furthermore, it ensures data compatibilitywith a digital communication device, a digital storage device, etc.

[0008] In the meantime, a new device is being developed to prepare forcommercialization of digital TV broadcast system. That is a digitalrecorder being able to receive TS of digital broadcast programs and torecord it on a writable HD-DVD. Such a digital recorder will be widelyused as the digital TV broadcast system is commercialized in earnest.

[0009] A single physical broadcast channel (called ‘RF channel’ ingeneral) has about 6 MHz bandwidth which ensures 19.4 Mbps data rate.This data rate can carry a single HD-TV broadcast signal or about fourSD-TV signals. Such a logical or virtual channel carrying one SD-TVsignal in an RF channel is called ‘digital channel’.

[0010] In other words, a single RF channel sometimes includes severaldigital channels, namely, sub-channels which carry mutually-differentbroadcast programs.

[0011] Therefore, a DVD recorder being developed may have to record twoor more digital channels simultaneously at a user's request. However, ifa DVD recorder records a plurality of digital channels and createsmanagement information through the same manner as it does for a singledigital channel, a DVD could not tell digital channels apart among arecorded stream of digital channels. Namely, a user could not selectonly one program, i.e., one digital channel to be reproduced among therecorded plurality of digital channels.

SUMMARY OF THE INVENTION

[0012] The recording medium according to the present invention includesa data structure for managing the reproduction of at least video datarepresenting multiple reproduction paths.

[0013] In one exemplary embodiment, a data area of the recording mediumstores a transport stream of at least video data. The transport streamis divided into transport packets, and each of the transport packets isassociated with one of the multiple reproduction paths. Also, thetransport packets of each reproduction path is stored in separatephysical domains of the data area from one another.

[0014] In another embodiment, the recording medium also includes anavigation area storing navigation information. The navigationinformation includes a map associated with each file, and each mapprovides position data for the video data of the associated file.

[0015] In a further exemplary embodiment, a navigation area of therecording medium includes a navigation data item. The navigation dataitem provides navigation information for reproducing each of the files.The navigation data item also includes a multiple reproduction pathindicator indicating that the navigation data item provides navigationinformation for multiple reproduction paths.

[0016] The present invention further provides apparatuses and methodsfor recording and reproducing the data structure according to thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are included to provide afurther understanding of the present invention, illustrate the exampleembodiments of the invention, and together with the description, serveto explain the principles of the present invention, and wherein:

[0018]FIG. 1 is a block diagram of an apparatus recording amulti-channel stream in accordance with the present invention;

[0019]FIG. 2 illustrates a series of transport packets belonging to twosub-channels outputted in the form of single stream ormutually-separated streams;

[0020]FIG. 3 illustrates the first embodiment of creating navigationdata for substreams of a plurality of digital channels recorded inplural high-density stream object units in accordance with the presentinvention;

[0021]FIGS. 4 and 5 are illustrative structures of navigation datacreated when a multi-channel stream is recorded as shown in FIG. 3;

[0022]FIG. 6 illustrates the second embodiment of creating navigationdata for substreams of a plurality of digital channels recorded inplural high-density stream object units in accordance with the presentinvention; and

[0023]FIG. 7 illustrates the third embodiment of creating navigationdata for substreams of a plurality of digital channels recorded inplural high-density stream object units in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

[0024] In order that the invention may be fully understood, an exampleembodiment thereof will now be described with reference to theaccompanying drawings.

[0025]FIG. 1 is a block diagram of an apparatus recording amulti-channel stream in accordance with the present invention.

[0026] The apparatus of FIG. 1 may be a digital video recorder (DVR)being able to record a digital broadcast signal on a recording medium,e.g., a writable HD-DVD. The apparatus comprises a tuner 10 tuning itspassband to at least one RF band of digital broadcast TV signal; astream selector 11 selecting a plurality of substreams belonging tochosen digital channels (or sub-channels) from a data stream of an RFchannel or channels passed by the tuner 10; a recording processor 12recording the selected substreams in a single HOB (High-Density StreamObject) or HOBs according to a preset recording mode, creating andwriting navigation data every a recorded substream; an optical pickup 13forming mark/space patterns on a HD-DVD 100 in accordance with bitpatterns of stream and navigation data outputted from the recordingprocessor 12; and a controller 14 conducting overall control operationsof all elements for multi-stream record.

[0027] The tuner 10 passes one digital broadcast TV channel, namely, anRF channel selected by the controller 14. The stream selector 11extracts transport packets (TPs) belonging to several, e.g., 2 digitalchannels selected through the controller 14 from a multi-channel streamof the RF channel passed by the tuner 10. The extracted series of TPs bythe stream selector 11 is outputted in the form of single stream 201 ormutually-separated streams 202 ₁ and 202 ₂, as illustrated in FIG. 2.

[0028] The tuner 10 can also pass multiple RF channels. In multiplepassing mode, the stream selector 11 is also able to extract more thanone substream from each RF channel to output a series of TPs belongingto digital channels chosen from available channels offered by respectiveRF channels.

[0029] For the convenience of explanation, it is supposed in allembodiments described in below that the stream selector 11 selects twosubstreams, namely, two digital channels from a received multi-channelstream.

[0030] The recording processor 12 can distinguish two digital-channelsubstreams, namely, the first and the second substream each other basedon packet ID (PID) written in every TP outputted from the streamselector 11.

[0031] The first and the second digital-channel substream are recordedaccording to a preset recording mode. If the preset recording mode is‘separate’, the recording processor 12 records two multiplexedsubstreams separately in two allocated HOBs 301 and 302 in the order asthey are received for each digital channel from the stream selector 12as shown in FIG. 3.

[0032] To separately record a plurality of substreams in plural HOBs,the recording processor 12 has enough buffering capacity. And, theoptical pickup 13 moves between allocated plural HOBs during databuffering of the recording processor 12 and it records the buffered datain a target HOB all at once.

[0033] Furthermore, the recording processor 12 creates navigation datafor each digital-channel substream, namely, for each HOB based on thedistinguished digital-channel information and each substream recordinginformation. The way how navigation data is created is described belowin detail.

[0034]FIG. 3 illustrates the first embodiment of creating navigationdata for substreams of a plurality of digital channels recorded inplural HOBs in accordance with the present invention.

[0035] A recording medium for recording a digital broadcast signal has aprovisional recording standard. According to the provisional recordingstandard, a recording medium shall have Program Chain Information (PGCI)prepared for index of every recorded program and for reproduction orderamong them. The PGCI includes Program Information (PGI) and CellInformation (CI) which are respectively created every a data streamcontinuously recorded from recording start to stop. Furthermore, asingle Presentation Time Map (PTMAP) shall be also created every arecorded data stream according to the provisional recording standard.The PTMAP, used for stream search, has collection of position data orposition-related time length data for every data unit constituting arecorded data stream. Search pointer and information of each PTMAP areincluded in HOB information (HOBI).

[0036] However, in the present recording method, not a single but pluralHOBs are formed through one-time recording of a multi-channel stream.Therefore, for two substreams separated in two HOBs, two pieces of PGI‘PGI #1 and PGI #2’ and two pieces of CI ‘Cell #1 and Cell #2’ arecreated and two pieces of PTMAPI for two PTMAPs are created too, asshown in FIG. 3.

[0037] The PGI and the CI are written in the PGCI while the two piecesof PTMAPI and the two PTMAPs are stored separately in the two pieces ofHOBI.

[0038] In general, navigation data such as PGCI and HOBI is loaded intoa memory (not figured) from the HD-DVD 100 during recording mode, andthe pieces of PGI, CI and HOBI created as above are inserted in thenavigation data which will be stored in a navigation data area of theHD-DVD 100 after the substreams of plural digital channels arecompletely recorded.

[0039]FIGS. 4 and 5 are illustrative structures of navigation datacreated when a multi-channel stream is recorded as shown in FIG. 3.

[0040] The PGCI of FIG. 4 includes program chain general information‘PGC_GI’, plural pieces of PGI ‘PGI #1 to #n’, a plurality of CI searchpointers ‘CI_SRP #1 to #m’, and plural pieces of CI ‘CI #1 to #m’. Eachpiece of PGI includes fields of program type ‘PG_TY’ and the number ofCI ‘C_Ns’. However, the number of CI ‘C_Ns’ may not be allocated since asingle piece of PGI is associated with a single piece of CI. Ifallocated, ‘1’ is always written in that field ‘C_Ns’.

[0041] The program type ‘PG_Y’, 8-bit long, includes ‘Protect’ flag toindicate whether an associated program (PG), equivalent to aconceptually-unitized stream, is erasable or not.

[0042] Each piece of CI is composed of cell type ‘C_TY’, HOBI searchpointer number ‘HOBI_SRPN’, and channel information ‘CHI’ consisting ofPTMAP number ‘PTMAPN’, start PTM of a cell ‘C_V_S_PTM’, and end PIM of acell ‘C_V_E_PTM’.

[0043] The field ‘C_TY’, 8-bit long, is composed of sub-fields of 2-bitcell type ‘C_TY1’, 3-bit channel number of a cell ‘C_CH_N’, andreserved. The sub-field ‘C_TY1’ indicates whether a cell is related withmulti-channel or single-channel stream. The sub-field ‘C_CH_N’ describesdigital channel number of a recorded substream in a HOB referred by acell.

[0044] For example, digital channel numbers of the first and the secondsubstream are respectively written in those sub-fields ‘C_CH_N’ of thetwo pieces of CI ‘CIs #1 and #2’ respectively referring to the HOBs 301and 302 of FIG. 3 in which two substreams of two digital channels areseparately included.

[0045] The HOBI, linked with the CI through the field ‘HOBI_SRPN’included in each piece of CI, comprises HOBI general information‘HOBI_GI’, a plurality of PTMAP search pointers ‘PTMAP_SRP #1 to #n’,and plural pieces of PTMAP information ‘PTMAPI #1 to #n’, as shown inFIG. 5.

[0046] The HOBI general information ‘HOBI_GI’ consists of many fields ofHOB type ‘HOB_TY’, HOB recording time ‘HOB_REC_TM’, start PTM of a HOB,end PTM of a HOB, the number of PTMAPs ‘PTMAP_Ns’, and start addressesof all PTMAPs ‘PTMAP_SA #i’.

[0047] The PTMAPI includes PTMAP general information ‘PTMAP_GI’ andentries of random accessible HOB units (HOBUs) ‘HOBU_ENT #1 to #j’. ThePTMAP general information ‘PTMAP_GI’ is composed of fields of video‘V_PID’ and audio packet ID ‘A_PID’, indicative of respective PIDs ofaudio and video TPs constituting a recorded stream associated with aPTMAP, HOBI index number ‘HOBI_STIN’, the number of random accessibleHOBUs ‘HOBU_ENT₁₃ Ns’, start PTM of a PTMAP ‘PTMAP_S_PTM’, and end PTMof a PTMAP ‘PTMAP_E_PTM’.

[0048] Since all substreams constituting a multi-channel stream areseparately recorded in plural HOBs and the navigation data structured asshown in FIGS. 4 and 5 is created and recorded for a recordedmulti-channel stream, a HOB containing a single substream of a digitalchannel to be reproduced can be determined based on information writtenin each piece of PGI and CI included in the PGCI, especially the channelnumber sub-field ‘C_CH_N’ allocated in the cell type ‘C_TY’.

[0049] When searching a substream of a chosen digital channel unitizedto a single HOB, a PTMAP associated with a substream of the chosendigital channel is determined first based on the information written inthe number of PTMAPs ‘PTMAP_Ns’, each PTMAP start address ‘PTMAP_SA #i’,and start and end PTM of a PTMAP ‘PTMAP_S_PTM’ and ‘PTMAP_E_PTM’ of thePTMAP general information ‘PTMAP_GI’ of each piece of PTMAP information‘PTMAPI #i’. Next, a substream in the determined HOB is searched andthen reproduced using PTM incremental time and size of each data unitwritten in the determined PTMAP.

[0050]FIG. 6 illustrates the second embodiment of creating navigationdata for substreams of a plurality of digital channels recorded inplural HOBs in accordance with the present invention.

[0051] This second embodiment of FIG. 6 is different from the first ofFIG. 3 in that a single piece of PGI is created for plural HOBs.However, a couple of PTMAP and PTMAPI used for searching substream iscreated every a HOB the same as the first embodiment, namely, as manypieces of PTMAP and PTMAPI as the number of digital channels arecreated.

[0052] Since this second embodiment is different from the first in thenumber of pieces of PGI created after recording substreams of aplurality of digital channels, the structure of the PGI is changed fromFIG. 4.

[0053] In this second embodiment, a piece of PGI covers a plurality ofsubstreams, which means that it is associated with plural pieces of CIeach of which covers a single substream. Therefore, the PGI shallaccompany the field ‘C_Ns’ to describe the number of pieces of CIassociated with it.

[0054] The program type ‘PG_TY’, besides ‘Protect’ flag, includes ‘S/M’flag and 3-bit number of channels ‘Channel_Ns’ where the ‘S/M’ indicateswhether an associated PG includes a single-channel or a multi-channelstream, and the number of channels ‘Channel_Ns’ describes the number ofdigital channels included in an associated PG.

[0055] Even in this second embodiment, all information on every recordedsubstream of every digital channel is included in navigation data thesame as in the first embodiment. Therefore, a substream of a selecteddigital channel only, which is unitized to a single HOB, can be searchedand reproduced among multiple substreams recorded simultaneously.

[0056]FIG. 7 illustrates the third embodiment of creating navigationdata for substreams of a plurality of digital channels recorded inplural HOBs in accordance with the present invention.

[0057] This third embodiment of FIG. 7 is different from the first ofFIG. 3 in that a single piece of PGI and CI is created respectively.However, the PTMAPI used for searching substream is created the same asthe first embodiment, namely, as many pieces of PTMAPI as the number ofdigital channels, equivalent to the number of created HOBs, contained ina multi-channel stream are created.

[0058] Since this third embodiment is different from the first in thenumber of pieces of PGI and CI created after recording substreams of aplurality of digital channels, minor modification is required in thestructure of navigation data of FIG. 4.

[0059] In this third embodiment, a piece of PGI covers a plurality ofsubstreams, therefore, the program type ‘PG_TY’, besides ‘Protect’ flag,includes the ‘S/M’ flag and the 3-bit number of channels ‘Channel_Ns’.Both sub-fields have been described in the second embodiment.

[0060] In this third embodiment, a piece of CI also covers a pluralityof substreams, therefore a piece of CI includes a ‘field of the numberof channels’ besides the fields of FIG. 4, and the channel information‘CHI’ composed of the PTMAP number ‘PTMAPN’, start PTM of a cell‘C_V_S_PTM’, and end PTM of a cell ‘C_V_E_PTM’ is created as many as thenumber of digital channels of a recorded multi-channel streamdistributed separately by channel in plural HOBs referred by the singlepiece of CI. In addition, an additional field for writing digitalchannel numbers is reserved in the CI since a single piece of CI coversall of digital channels contained in a recorded multi-channel stream.

[0061] Since the CI also has information on the number of channels of arecorded stream, the sub-field ‘Channel_Ns’ for the number of channelsneed not be allocated in the PGI. In addition, because a single piece ofCI is created even though a stream of a plurality of digital channels isrecorded, the field ‘C_Ns’ indicative of the number of pieces of CI canbe removed from the PGI of FIG. 4.

[0062] Even in this third embodiment, all information on every substreamof every digital channel is stored in navigation data the same as in thefirst embodiment. Therefore, a substream of a selected digital channelonly, which is unitized to a single HOB, can be searched and reproducedamong multiple substreams recorded simultaneously.

[0063] The above-explained multi-channel stream recording method andapparatus make it possible to selectively search and reproduce eachsubstream among a multi-channel stream recorded on a recording medium,thereby improving use convenience of a recording machine such as adigital video recorder.

[0064] It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A recording medium having a data structure formanaging reproduction of at least video data representing multiplereproduction paths, comprising: a data area storing a transport streamof at least video data, the transport stream being divided intotransport packets, each of the transport packets associated with one ofthe multiple reproduction paths, and the transport packets of eachreproduction path being stored in separate physical domains of the dataarea from one another.
 2. The recording medium of claim 1, furthercomprising: a navigation area storing navigation information, thenavigation information including a map associated with each reproductionpath, each map providing position data for the video data of theassociated reproduction path.
 3. The recording medium of claim 2,wherein the navigation area includes a navigation data item, thenavigation data item providing navigation information for reproducingeach of the multiple reproduction paths.
 4. The recording medium ofclaim 3, wherein the navigation area includes a navigation list, thenavigation list including at least the navigation data item.
 5. Therecording medium of claim 4, wherein the navigation data item includes amultiple reproduction path indicator indicating that the navigation dataitem provides navigation information for multiple reproduction paths. 6.The recording medium of claim 3, wherein the navigation data itemincludes a multiple reproduction path indicator indicating that thenavigation data item provides navigation information for multiplereproduction paths.
 7. The recording medium of claim 1, wherein eachreproduction path represents a digital channel.
 8. The recording mediumof claim 1, wherein each reproduction path represents a sub-channel ofan RF channel.
 9. A recording medium having a data structure formanaging reproduction of at least video data representing multiplereproduction paths, comprising: a navigation area storing a navigationdata item, the navigation data item providing navigation information forreproducing each of the multiple reproduction paths and providing amultiple reproduction path indicator indicating that the navigation dataitem provides navigation information for multiple reproduction paths.10. The recording medium of claim 9, wherein the navigation areaincludes a navigation list, the navigation list including at least thenavigation data item.
 11. The recording medium of claim 9, wherein eachreproduction path represents a digital channel.
 12. The recording mediumof claim 9, wherein each reproduction path represents a sub-channel ofan RF channel.
 13. A method of recording a data structure for managingreproduction of at least video data representing multiple reproductionpaths, comprising: recording a transport stream of at least video dataon the recording medium, the transport stream being divided intotransport packets, each of the transport packets associated with one ofthe multiple reproduction paths, and the transport packets of eachreproduction path being stored in separate physical domains of the dataarea from one another.
 14. A method of reproducing a data structure formanaging reproduction duration of at least video data representingmultiple reproduction paths, comprising: reproducing a transport streamof at least video data from the recording medium, the transport streambeing divided into transport packets, each of the transport packetsassociated with one of the multiple reproduction paths, and thetransport packets of each reproduction path being stored in separatephysical domains of the data area from one another.
 15. An apparatus forrecording a data structure for managing reproduction duration at leastvideo data representing multiple reproduction paths, comprising: adriver for driving an optical recording device to record data on therecording medium; a controller for controlling the driver to record atransport stream of at least video data on the recording medium, thetransport stream being divided into transport packets, each of thetransport packets associated with one of the multiple reproductionpaths, and the transport packets of each reproduction path being storedin separate physical domains of the data area from one another.
 16. Anapparatus for reproducing a data structure for managing reproductionduration of at least video data representing multiple reproductionpaths, comprising: a driver for driving an optical reproducing device toreproduce data recorded on the recording medium; a controller forcontrolling the driver to reproduce a transport stream of at least videodata from the recording medium, the transport stream being divided intotransport packets, each of the transport packets associated with one ofthe multiple reproduction paths, and the transport packets of eachreproduction path being stored in separate physical domains of the dataarea from one another.